Electric transmission of power.



Patented Nov. 26, |90I. l

- .1. B. HALL. ELECTRIC TRANSMISSION 0F POWER.

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UNITED STATES PATENT OFFICE.

JOSEPH B. IIALII, OF CHICAGO, ILLINOIS'.

ELECTRIC TRANSMISSION OF POWER.

:SPECIFICATION forming part of Letters Patent No. 687,623, datedNovember 2 1901.

Application led February 4, 1901. Serial No. 45,937. (No model.)

To @ZZ whom it may concern:

Be it known that I, JOSEPH B. HALL, of Chicago, county of Cook, andState of Illinois, have invented an Improvement in Electric Transmissionof Power, of which the following description, in connection with theaccompanying drawings, is a specication, like letters representing likeparts.

This invention relates to electric generators or electric transformerswhen used as torque producing or accelerating or variable-speedmechanisms, and provides a means of obtaining a useful pull with aminimum expenditure of energy. When used for the above purpose, electricgenerators of the usual types or the Variarotor speed-varying mechanismof my invention-Serial No. 28,617, filed August 30, l900the productionof a useful pull is by means of induced currents in short-circuitedwindings (when the two rotating parts are not in synchronism) and isexpensive in energy. To obtain great economy, I place in circuit withthe inductors an inductive resistance, which permits a Wattless currentof high amperage to pass, and thus obtain the desired torque. Of coursewith generators giving unidirection currents by means of a commutatorthe inductive resistance is placed in the circuit between the commutatorand the inductor's.

By the term inductive resistance is meant a coil consisting of one ormore turns of electric conductor Wound around a laminated iron or steelcore, forming a closed or nearly closed magnetic circuit, withalternating or pulsating currents traversing the conductors. By the terminductor is meant a conductor of electricity moving in a magnetic field,thus producing an electromotive force.

The invention consists of one portion of a magnetic circuit connected toa source of power on which electric conductors are wound, anotherportion of a magnetic circuit on which a second set of conductors areWound and which is connected to the machine to be driven, a source ofelectricity, (either direct or alternating,) an inductive resistanceconnected to the other set of conductors, which thus become inductors,and means for varying the torque, which may be done'by altering theself-induction of the inductive resistance or by changing theexciting-current from the ance, also in circuit with thearmature-inductors through slip-rings. Fig. 3 shows a diagrammaticalview of the Variarotor heretofore mentioned, with both theexciting-coils and the inductor-coils mounted on the exterior rotatingpart of the magnetic circuit, the inductors being connected by means ofsliprings and brushes. to a variable inductive resistance. Fig. e is alongitudinal section of the generator diagrammed in Fig. I. Fig. 5 is alongitudinal section ofthe form of generator diagrammed in Fig. 2. Fig.6 shows a longitudinal section of the Variarotor diagrammed in Fig. 3.Figs. 7, 8, and 9 are respectively partial views-a longitudinal section,an end view, and a plan-of one method of mounting a variable inductiveresistance on the part carrying the inductors I.

In Figs, I and 4 the armatureA is mounted on shaft S by means of spiderQ, the armature-inductorsI being connected to inductive resistance R(with movable iron core T) by means of brushes B and slip-rings N. Theheld-coils C are connected to a source of electricity E by means ofslip-rings M and brushes D. The field M is mounted, but free to rotate,on shaft S by means of spider L, which rotates in a bearing in frame K.Power is received and transmitted at .I and .I.

In Figs. 2 and 5 the armature A is mounted on shaft S by means of spiderQ. The armature-inductors I are connected to field-coils C through acommutator P and brushes D, thus furnishing the means of excitation. Theinductors I are also connected to a variable ohmic resistance Z and avariable inductive resistance R (with movable core T) by means ofslip-rings N and brushes B. The field M is IOO mounted on spider L,supported in a bearing in frame K. Means for receiving and transmittingpower J and Jn are provided the shaft S and spider L.

In Figs. 3 and G the exciting-coils C are mounted on part X of themagnetic circuit, and by means of slip-rings M and brushes D areconnected to variable ohmic resistance Z and source of electricity E.The inductors I are also mounted on part X and by means of slip-rings Nand brushes B are connected to inductive resistance R, having a movablecore T. Part W of the magnetic circuit is mounted on shaft S, whichrotates in bearings formed in frame K and spider L. Part X is mounted onspiders L and L, which rotate on shaft S, spider L also rotating in abearing in frame K. Power is received and transmitted by means ofJ andJn.

In all figures Da and Ba are supports of insulating material for holdingthe brushes D and B.

In Figs. '7, 8, and 9 is shown one of the arrangements whereby avariable inductive resistance may be mounted on and rotate with the partcarrying the inductors I. A is the armature mounted on shaft S by meansof spider Q, the inductors I being wound on armature A, and oneinductor-terminal being connected to an end of coil R, wound on ironcore T, which core is mounted on shaft S bymeans of spider Qa. Thereturn-'circuit from coil Ra to inductors I is through brush Bb, whichis in contact with the turns of coil R and movable over the coil R(cutting the turns in and out of circuit) by means of arm B, whichlatter is rotatable around shaft S by means of bevel-gear Bd, whichmeshes into bevel-gear Hb, mounted on pivot Hd, which is fixed to shaftSby means of collar Hc. Pin He, fastened to wheel Hb, engages in arm Il,which is part of sliding collar H, the latter being movable along theshaft by lever G, of which lugs G1 engage in a circumferential groove insleeve H. The lever G has its fulerum at G and may be operated manuallyor otherwise.

With the electric conductors moving in a magnetic field of five thousandcentimetergram-second lines to produce a pull of about 3.42 poundsrequires a current of one hundred amperes per foot of active conductor.With the inductors short-eircuited on themselves or connected to ohmicresistance the energy absorbed by the inductors when producing a usefulpull is about equivalent to the amount of power transmitted, so such anarrangement would have a commercial efficiency at full load of less thanfifty per cent., while if the same magnetic flux is used and theinductors be increased to ten times the area that could possibly be usedWithout inductive resistance and an inductive resistance be placed incircuit with the inductors, so that the same number of amperes (uponwhich the torque is dependent when the parts are not in synohronism) bepermitted to iiow estacas as in the original arrangement, then but alittle more than ten per cent. of the energy transmitted would beexpended in the necessary torque production.

In any generator such as is shown in Figs. 1 and 2, where the magneticpolar projections on armature A are not the same number' as those of eldF, when transmitting power the speed of one rotating part can never bethat of the otheri. e., in synchronism-except when caused by thefrietional drag of the bearings, while in the form of magnetic circuitshown in Fig. 3 when transmitting power or otherwise one part may bemade to rotate at any speed from a state of rest to that of the other,as desired. lVith either arrangement, as shown iu Figs. 1, 2, and 3, thevariable inductive resistance may be fixed to and rotate with the partcarrying the inductors, thus obviating the use of slip-rings N andbrushes B, or by using slip-rings N and brushes B the inductors andinductive resistance so arranged may be connected to a variable ohmieresistance.

While the preferable way to alter the torque is to vary the inductiveresistance, yet the same results may be obtained by changing themagnetism and at the moment of starting eut out the inductiveresistance, inserting it as the speed increases, or where a largestarting torque is not required by dispensing with the adjustment of theinductive resistance and simply Vary the exciting-current.

I claim#- 1. The combination with a member to be rotated, of a source ofpower, a two-part generator, one part of which is connected with themember to be rotated and the other part of which is connected to androtated by the source of power, whereby rotation by the source of powerof one part of said generator with relation to the other part togenerate a current of electricity causes said other part also to rotateand thereby act as a clutch to rotate the member to be rotated; aninductive resistance in circuit with the armature-inductors of thegenerator and means for varying the torque of the generator,substantially as described.

2. The combination with a member to be rotated, ofa source of power, atwo-part generator having the same number of magnetic polar projectionson both parts, one part of which is connected to the member to berotated, and the other part of which is connected to and 'rotates withthe source of power, whereby r0- tated until both rotating parts are insynwith the said inductors, together with means for Varying the torque,substantially as described.

3. An axle in combination with a source of power and a. two-partgenerator, one part of which generator is connected with and rotated bythe source of power, the other part being connected to the axle,together with a means

